Early engineering work in rocketry in America was performed by Dr. Robert Goddard (1882-1945). Subsequent to 1945, additional progress was made by teams headed by Dr. Wernher von Braun (1912-1977). This led to the creation in 1958 of the US National Aeronautics & Space Administration (NASA) which maintains launch facilities in Florida, now known as the Kennedy Space Center (KSC). The US Department of Defense (DoD) also maintains a launch facility at Vandenberg Air Force Base in California. Contractors for NASA and the DoD have developed technology to maximize launch success and to minimize damage to launch facilities, resulting from degradation by hot gases and flying debris.
During a development program (circa 1957-78) for the Titan I rocket, a flame deflector having a generally J-shaped radial cross-section, with a horizontal exit for the flames, was developed. Two J-shaped structures can be used, so that their respective exits point in opposite directions along a common axis, as shown in FIG. 1 on page 3 of the April 2010 AIAA Conference Report cited above. The basic structure is a metal base framework, on which is applied a rocket-facing protective layer of Portland cement. Subsequent launchpads, dealing with more severe conditions, used a refractory material sold by the Pryor Giggey Co. of Alabama under the trademark FonduFyre, as described in the above-cited Martin-Marietta Design Handbook. As of this writing, FonduFyre is the only refractory material approved by the Kennedy Space Center to protect flame-impinged surfaces. The KSC acknowledges, in its 2009 technical reports, that there are problems associated with FondueFyre, and has sought to determine whether alternative refractory materials would meet the performance requirements for KSC's launchpad technical application. However, to the best of my knowledge, no changes have been made since 2009 by the KSC to its list of approved refractory materials. This FondueFyre cement has generally been applied to the metal base by spraying, on location, in a manner analogous to construction of a swimming pool, known colloquially as “guniting.” Experience has shown that the structures produced in this manner fail to exhibit uniformly high resistance to rocket flames, and often need to undergo expensive repairs after a launch. Further, the refractory surface is also vulnerable to tropical rains, salt deposition, and other adverse environmental influences. A series of NASA reports detail various attempts at a solution, with less-than optimal results. See the April 2010 AIAA Conference Paper, referenced above.